Presenter Information

Kelsey HefnerFollow

Presentation Type

Poster

Start Date

5-8-2024 11:00 AM

End Date

5-8-2024 3:00 PM

Subjects

Atmospheric chemistry--Congresses

Advisor

Dr. Kelly Gleason

Student Level

Undergraduate

Abstract

Natural and anthropogenically sourced particulates are deposited from the atmosphere to landscapes via dry and wet deposition, making frozen winter snowpack a natural archive of atmospheric elemental composition. Wildfires in the Western United States are increasing in extent, duration, and severity, especially in alpine regions. Severe fires remove forest canopy and can impact how atmospheric elements are dispersed and stored across snow-dominated watersheds. We evaluated Al, V, Cr, Mn, Ni, Cu, As, Zn, Se, Mo, Cd, and Pb concentrations in 394 winter snow core samples. We collected samples in 2019 and 2020 from a chronosequence of eight forests that burned with mixed severity from 2000 to 2018 in the Triple Divide region of Western Wyoming. We compared concentrations of significant elements Al, V, Mn, As, and Pb by fire and forest structure, and we classified them into three forest types: unburned forests, burned forests, and open meadows. Two fire scars south of Jackson Hole showed the highest average concentrations of all significant elements. Concentrations of Al, V, Mn, As, and Pb in unburned forests were at least double that of burned forests and open meadows (p < 0.05), likely due to the forest canopy and boundary layer turbulence effects.

Creative Commons License or Rights Statement

Creative Commons Attribution 4.0 License
This work is licensed under a Creative Commons Attribution 4.0 License.

Persistent Identifier

https://archives.pdx.edu/ds/psu/41871

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May 8th, 11:00 AM May 8th, 3:00 PM

Multiscale Variability of Heavy Metals in a Western U.S. Snowpack

Natural and anthropogenically sourced particulates are deposited from the atmosphere to landscapes via dry and wet deposition, making frozen winter snowpack a natural archive of atmospheric elemental composition. Wildfires in the Western United States are increasing in extent, duration, and severity, especially in alpine regions. Severe fires remove forest canopy and can impact how atmospheric elements are dispersed and stored across snow-dominated watersheds. We evaluated Al, V, Cr, Mn, Ni, Cu, As, Zn, Se, Mo, Cd, and Pb concentrations in 394 winter snow core samples. We collected samples in 2019 and 2020 from a chronosequence of eight forests that burned with mixed severity from 2000 to 2018 in the Triple Divide region of Western Wyoming. We compared concentrations of significant elements Al, V, Mn, As, and Pb by fire and forest structure, and we classified them into three forest types: unburned forests, burned forests, and open meadows. Two fire scars south of Jackson Hole showed the highest average concentrations of all significant elements. Concentrations of Al, V, Mn, As, and Pb in unburned forests were at least double that of burned forests and open meadows (p < 0.05), likely due to the forest canopy and boundary layer turbulence effects.